1. Field of the Invention
The present invention relates to a personal digital assistant (PDA) phone, and more particularly, to a power consumption control apparatus in a PDA phone.
2. Description of the Background Art
In general, a personal digital assistant (PDA) is a kind of hand-held (pocket-size) microcomputer. The PDA is typically used for arrangement schedule, memo writing and personal information management. In addition to the arrangement schedule, the PDA can be also used for the field of the mobile Internet or the like. In other words, the PDA can be considered as equipment in which various control functions and an Internet access function of a notebook computer are put together with a small size of electronic organizer.
Recently, as interest in PDAs increases, the number of users has grown larger. A PDA phone which has the cellular phone function in addition to various functions of the PDA has come into the market. Since the PDA phone converges the functions of the PDA and the phone function, it is necessary that operation methods for the PDA phone should be arranged according to various states.
As functions of user equipment driven by portable batteries such as smart phones and PDA phones become complicated and varied, and the performance of user equipment is enhanced, power consumption per unit of time is considerably increased. Accordingly, in order to reduce the power consumption of the user equipment, controlling the power for software and hardware becomes more important to design the user equipment. Hardware components such as a CPU, a memory device, an LCD and the like which constitute the user equipment cause this multifunction, high-performance user equipment to consume much power.
Particularly, a PDA phone in accordance with the conventional art comprises a sleep mode, an idle mode, a called mode, an in-call mode and a calling mode. A mode of the PDA phone in accordance with the conventional art can be transitioned only from the sleep mode to the idle mode. The mode of the PDA phone in accordance with the conventional art can be transitioned only from the idle mode to the sleep mode.
Hereinafter, a state transition of the conventional PDA phone will be described in detail with reference to FIG. 1.
FIG. 1 is a state transition diagram of a PDA phone in accordance with the conventional art.
As shown in FIG. 1, when a user wakes up the PDA phone, a sleep mode 11 is transitioned to an idle mode 12 (S11). In a state of the idle mode 12, the idle mode 12 is transitioned to the sleep mode 11 automatically after a certain amount of time or by user's input signal (S12).
When a call signal is received in the state of the idle mode 12, the idle mode 12 is transitioned to a called mode (S13). If the call signal is not accepted in a state of the called mode 13, that is, if the user does not answer the phone, the called mode 13 is transitioned to the idle mode 12 (S14).
If the received call signal is accepted in the state of the called mode 13, that is, if the user answers the phone, the called mode 13 is transitioned to the in-call mode 14 (S15).
In addition, if the user presses a telephone number signal in order to make a phone call with the other party in the state of the idle mode 12, that is, sends a call signal, the idle mode 12 is transitioned to a calling mode 15 (S16). If the user cancels the sent call signal in a state of the calling mode 15, that is, if the user stops making a phone call, the calling mode 15 is transitioned to the idle mode 12 again (S17).
If the other party accepts the call signal in the state of the calling mode 15, that is, if the other party answers the phone, the calling mode 15 is transitioned to the in-call mode 14 (S18).
If the call signal is terminated in a state of the in-call mode 14, that is, if the user terminates the call, the in-call mode 14 is transitioned to the idle mode 12 (S19).
Here, the sleep mode 11 cannot be implemented by the user. In the sleep mode 11, a screen of the PDA phone is turned off, touch input and keypad input cannot be made and a state only for answering the phone is maintained. Accordingly, the PDA phone operates in the sleep mode 11 at the minimum power.
The idle mode 12 is a state that the power which is applied to a CPU, a cache and a buffer is cut off. In addition, the idle mode 12 is a mode that when an interrupt occurs, the sleep mode, the called mode, the in-call mode and the calling mode return. Here, in the idle mode 12, user's operation is all allowed, the screen of the PDA phone is turned on, and touch input and keypad input can be made. That is, the idle mode is a state only for the PDA purpose. Since the PDA phone operates in the idle mode 12 with a certain amount of power internally consumed, the PDA phone consumes more power in the idle mode than in the sleep mode 11.
The called mode 13 is a state that the call signal sent by the other party is received and a telephone bell rings before the phone call is connected. Therefore, the PDA phone consumes more power in the called mode 13 than in sleep mode 11.
The in-call mode 14 is a state that voice communication with the other party is performed. Accordingly, the PDA phone consumes more power in the in-call mode 14 than in the sleep mode 11.
The calling mode 15 is a state that the user sends a call signal before the phone call is connected. Accordingly, the PDA phone consumes more power in the calling mode 15 than in the sleep mode 11.
However, since the PDA phone in accordance with the conventional art maintains the called mode, the in-call mode and the calling mode even in unnecessary steps, there is a problem that the PDA phone consumes much power. In addition, the conventional PDA phone is unable to cope with the circumstances which may occur in every state.